alpha-chloro-beta-alkoxy-butyraldehydes and process of preparing them



Patented Mar. 17, 1942 UNITED Price a-CHLORO l8 ALKOXY-BI JTYRALDEHYDES AND PROCESS OF PREPARING THEM Walter Ostrowski and Otto Nicodemus, Frankfort-on-the-Main, Germany, assignors, by

mesne assignments, to General Aniline & Film Corporation, New York, N. Y., a corporation of Delaware No Drawing. Application May 3, 1939, Serial No. 271,514. In Germany May 9, 1938 13 Claims.

CH3.CH=CC1.CHO

forming addition products in good yield. As alkaline agents there may be used any of the substances suitable for alkaline condensations; alkali metal hydroxides such as sodium hydroxide or potassium hydroxide have been found to be superior for the purpose in comparison with other alkaline agents, for instance potassium carbonate or sodium carbonate, furthermore potassium alcoholate or sodium alcoholate, but these may likewise be used. The alkaline agent may be used, for instance, in a ratio of about 1 to 200 to about 1 to 400.

The reaction is preferably carried out at temperatures between about l C. and about +10 C.

As alcohols there may, for instance, be used: methyl alcohol, ethyl alcohol, propyl alcohol.

The reaction is suitably carried out in the presence of such an excess of the alcohol that the alcohol serves as solvent.

During the reaction compounds of the formula HsC-CH-CH-CHO 0 to +5 C., while stirring, into 5 liters of methanol to which about 20 cc. of caustic soda solution of 33 per cent strength have been added. After the introduction is complete, about 5 cc. of the caustic soda solution are further added. The mixture is allowed to stand over night at 0 C.; it then shows only a feebly alkaline reaction to turmeric paper. For the further treatment the mixture is just acidified with a small quantity of glacial acetic acid and the methanol is distilled under reduced pressure at as low a temperature as possible. The remaining aldehyde is first distilled under a pressure of 10 mm., while the temperature inside the vessel is raised to 100 C., and then fractionated. 1600 grams of m-chloro-B-methoxybutyraldehyde are obtained boiling at 48 C. to 50 C. under a pressure of 10 mm.; this yield is 65 per cent of the theoretical yield, without considering the non-transformed I chlorocrotonic aldehyde which can be used again. (2) As described in Example 1, ethanol is added to u-chlorocrotonic aldehyde. There is obtained in nearly the same yield a-chlOI'O-B-GthDXY- butyraldehyde boiling at C. to 56 C. under a pressure of 10 mm.

We claim:

1. The process of preparing u-chloro-fialkoxy butyraldehyde which comprises causing a lower saturated aliphatic primary alcohol to act upon a-ChlOIOClOtOI'liC aldehyde in a solution of an alkaline compound of an alkali metal at a temperature lower than about+10 C.

2. The process of preparing oz-ChlOlO-B-EJKOXY butyraldehyde which comprises causing a lower saturated aliphatic primary alcohol to act upon achlorocrotonic aldehyde in a solution of an alkaline compound of an alkali metal in an excess of said lower saturated aliphatic alcohol as a solvent at a temperature of between about l0 C. and about +10 C. p

3. The process as defined in claim 1 wherein the alkaline compound is an alkali metal hydroxide.

4. The process as defined in claim 2 wherein the alkaline compound is an alkali metal hydroxide.

5. The process as defined in claim 1 wherein the alkaline compound is an alkali metal carbonate.

6. The process as defined in claim 2 wherein the alkaline compound is an alkali metal carbonate.

'7. The process as defined in claim 1 wherein the alkaline compound is an alkali metal alcoholate of a lower saturated alcohol.

8. The process as defined inclaim 2 wherein the alkaline compound is an alkali metal alcoholate of a lower saturated alcohol.

9. The process of preparing d-ChlOlO-fi-fiJkOXY butyraldehyde which comprises causing methyl alcohol to act upon oz-ChlOIOCIOtOIllC aldehyde in a solution of sodium hydroxide and of an excess of methyl alcohol at a temperature between about 0 C. and about +5 C.

10. The process of preparing a-ChlOIO-B-EtlkOXY butyraldehyde which comprises causing ethyl alcohol to act upon oz-ChlOlOClOtOlllC aldehyde in a solution of sodium hydroxide and of an excess of ethyl alcohol at a temperature between about C. and about +5 C.

11. The compounds of the following formula HaCCH-CHCHO I OR Cl wherein R. stands for a lower aliphatic saturated 12. The tr-ChIOIO p methoxy butyraldehyde, being a clear, colorless liquid, boiling at about 48 C. to 50 C. under a pressure to 10 millimeters.

13. The a-chloro-,B-ethoxy-butyraldehyde, being a clear, colorless liquid, boiling at about C. to 56 C. under a pressure of 10 millimeters.

WALTER OSTROWSKI. OTTO NICODEMUS. 

